A. Field of the Invention
The present invention relates generally to the field of basic process function controllers, thermostatically controlled apparatus and oven control arrangements and more particularly to the locking of the oven door of a self-cleaning oven under predetermined operating conditions and the unlocking of the oven door of the self-cleaning oven during predetermined operating modes.
B. Description of the Prior Art
Oven control apparatus and self-cleaning ovens of the prior art provide various arrangements for controlling the latching or locking of the oven door of a self-cleaning oven while the self-cleaning cycle is in process and the temperatures of the oven are elevated above normal cooking temperatures. The control arrangements of the prior art provide various arrangements including separate thermostatic arrangements for each of the functions of controlling cooking temperatures of the oven, controlling self-cleaning temperatures of the oven, and controlling the locking of the oven door when the oven temperature is above a predetermined temperature.
For example, reference may be made to U.S. Pat. No. 3,121,158, which issued to B. Hurko on Feb. 11, 1964, for a detailed consideration of self-cleaning ovens and the general nature of the self-cleaning cycle.
Further, various control arrangements to provide locking of the oven door during the self-cleaning cycle and during predetermined high temperature operation are disclosed in U.S. Pat. Nos.: Re. 26,943 which issued to R. B. Barber on Aug. 25, 1970; Re. 26,944 which issued to C. Getman on Aug. 25, 1970; 3,655,943 which issued to C. J. Holtkamp on Apr. 11, 1972; 3,469,568 which issued to S. H. Torrey, et al. on Sept. 30, 1969; 3,569,670 which issued to C. A. Eff on Mar. 9, 1971; 4,109,637 which issued to C. Drouin on Aug. 29, 1978; Re. 27,276 which issued to K. H. Erickson on Jan. 18, 1972; Re. 27,291 which issued to R. V. Fowler on Feb. 22, 1972; Re. 27,545 which issued to W. R. Guy on Jan. 9, 1973; 3,094,605 which issued to S. B. Welch on June 18, 1963; 3,362,398 which issued to W. H. Fane, Jr. on Jan. 9, 1968; 3,384,071 which issued to W. K. Body, et al. on May 21, 1968; 3,412,235 which issued to H. F. Hild, et al. on Nov. 19, 1968; 3,412,236 which issued to H. F. Hild, et al. on Nov. 19, 1968; 3,474,226 which issued to H. A. Kauranen on Oct. 21, 1969; 3,484,858 which issued to S. C. Jordan, et al. on Dec. 16, 1969; 3,549,862 which issued to C. J. Holtkamp on Dec. 22, 1970; 3,750,643 which issued to R. V. Fowler, et al. on Aug. 7, 1973; 3,757,084 which issued to McLean, et al. on Sept. 4, 1973; 3,894,214 which issued to P. R. Staples on July 8, 1975; and 4,013,312 which issued to R. P. DeWeese on Mar. 22, 1977.
While the arrangements of the prior art are generally suitable for their intended purpose, the prior art arrangements require separate oven control thermostats and door locking thermostats and various independent contact arrangements commonly using bimetal thermostatic switches. The aforementioned prior art arrangements thus suffer from reliability problems due to the various thermostatic arrangements and also entail complicated arrangements for the separate functions and their controlled interrelationships.